Last updated: August 21, 2025
In September, Nanjing experiences a diverse range of weather conditions, with temperatures peaking at a maximum of 39°C (102°F) and averaging around 24°C (76°F). The nights offer a reprieve with minimum temperatures dropping to 17°C (63°F). Rainfall is a notable feature this month, accumulating to 157 mm (6.2 in) over approximately 16 days, contributing to the area's high humidity level of 84%. This combination of heat and moisture creates a muggy atmosphere, making it essential for locals and visitors alike to stay hydrated and prepared for sudden rain showers.
In September, Nanjing experiences a delightful transition as the summer heat begins to wane. With a minimum temperature of 17°C (63°F) and an average of 24°C (76°F), the city feels comfortably warm, though the maximum can soar up to 39°C (102°F) on particularly hot days. This month marks a noticeable shift from the intense heat of July and August, where temperatures consistently exceeded 40°C (104°F). As the cool air of autumn approaches, September serves as a perfect blend of summer warmth and the anticipation of cooler days ahead, enticing locals and visitors alike to enjoy the vibrant atmosphere of this historic city.
In September, Nanjing experiences a notable shift in precipitation, recording 157 mm (6.2 in), which marks one of the wettest months of the year. This uptick follows the intense rainfall of July, peaking at 205 mm, and continues the trend of significant moisture that begins with the spring melt. Sixteen days of rain contribute to this accumulation, underscoring a seasonal pattern where late summer transitions into a wetter autumn. As the city braces for October's drier forecast of 108 mm, the September showers not only replenish the landscape but also set the stage for the lush and vibrant fall that follows.
As September rolls into Nanjing, China, the humidity remains notably high, measuring at 84%. This figure reflects a slight decrease from the peak of 87% seen in August but still maintains a level consistent with the late summer months. Throughout the year, Nanjing experiences a gradual increase in humidity from a moderate 72% in January, culminating in the highest values of 85% in both June and July, before tapering down in the autumn. The subtle fluctuations of humidity suggest a transition period as the city shifts from the hot, sticky conditions of summer toward the cooler, more comfortable climate of October.
As summer transitions into autumn in Nanjin, China, September marks the continuation of an intense sun exposure period with a UV Index of 11, categorized as extreme. This level of intensity requires vigilance, as the burn time is notably short at just 10 minutes. The trend from May through September reveals a persistent peak UV Index, indicating that outdoor enthusiasts must take precautions to avoid sunburn and protect their skin. Following September, a slight decline is expected in October, where the UV Index dips to 8, but the high levels experienced throughout the summer serve as a stark reminder of the region's sun intensity. For more insights on the UV Index in Nanjin, check out Nanjin UV Index.
UV Risk Categories
As September rolls in, Nanjing enjoys a vibrant slice of sunshine, with 225 hours illuminating the city. This month marks a transition, gently descending from the peak summer brightness of 318 hours in August. Despite the slight decrease, September continues to bask in plentiful sunlight, outshining the earlier months of the year, which start from a modest 129 hours in January. The overall trend shows a steady rise in sunny days from the depths of winter to the height of summer, peaking mid-year. As autumn approaches, the golden rays linger, creating an inviting atmosphere ripe for exploration and savoring the last warmth of the season.
In Nanjing, China, September enjoys a 33% chance of sunny weather, tying with January and July for the highest likelihood of clear skies throughout the year. As summer wanes, the sun's presence remains significant, providing a refreshing daylight experience before the cooler autumn months set in. Notably, this is a contrast to the preceding months, where the likelihood of sunshine dips, particularly in April and June, which see the lowest chances at just 14% and 13%, respectively. This trend highlights September as a favorable time for outdoor activities, making it an ideal month for locals and visitors alike to soak up the sun before the seasonal shift.
As summer transitions into autumn, September in Nanjing, China, offers a pleasant daylight duration of 12 hours. This month marks a subtle decline from the longer days of the summer months, peaking at 14 hours in June. Following July and August, which maintain a consistent 13 hours, September serves as a gentle reminder of the approaching fall, as daylight gradually diminishes. Observing the trend throughout the year, it’s clear that daylight duration follows a cyclical pattern: starting at a modest 10 hours in January, it escalates to its zenith in the middle of the year before tapering back down. This rhythm not only shapes daily life but also enhances the beauty of Nanjing's changing seasons.
As September rolls in Nanjing, China, the city feels the gentle embrace of the breeze, with an average wind speed of 1.9 m/s (4 mph). This marks a slight uptick from the summer months, signaling a transition into the cooler autumn air. Throughout the year, wind speeds fluctuate, but September stands out as a refreshing moment, with winds gradually increasing from the lulls of July and August. While the winds are consistently mild, hovering around 4 mph for most months, the shift in September hints at nature’s preparation for the vibrant fall season, inviting a sense of renewal and anticipation across the landscape.
Weather in Nanjin varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Nanjin, focusing on differences in temperature, rainfall, humidity, and UV levels.
September weather is characterized by warm temperatures, ranging from a minimum of 17°C (63°F) to a maximum of 39°C (102°F), with an average of 24°C (76°F). This month experiences significant rainfall, totaling 157 mm (6.2 in) over about 16 days, along with high humidity levels at 84%.
In contrast, January brings much cooler conditions, with temperatures dipping to a minimum of -2°C (29°F) and a maximum of 17°C (62°F), resulting in a much lower average of 9°C (48°F). Precipitation is minimal at 23 mm (0.9 in) across just 5 days, and humidity is comparatively lower at 72%.
For more detailed insights into the January weather, you can visit Nanjin weather in January.
September and February present starkly contrasting weather conditions. In September, temperatures can soar from a minimum of 17°C (63°F) to a scorching maximum of 39°C (102°F), accompanied by considerable humidity at 84% and substantial rainfall totaling 157 mm (6.2 inches) across 16 days. In contrast, February experiences much cooler temperatures, with averages around 10°C (51°F), peaking at 27°C (80°F) and dipping to a chilly 1°C (35°F). Furthermore, precipitation is significantly lower in February, with only 32 mm (1.3 inches) measured over just 6 days, and humidity also decreases to 76%. For a deeper dive into February weather specifics, you can check Nanjin weather in February.
Comparing the weather in September and March reveals notable differences in temperature and precipitation patterns. September typically experiences warmer temperatures, with a minimum of 17°C (63°F) and an average of 24°C (76°F), reaching highs of up to 39°C (102°F). In contrast, March has cooler temperatures, starting at a minimum of 6°C (44°F) and averaging 16°C (60°F), with a maximum of 33°C (91°F). Additionally, September sees significantly more rainfall, accumulating 157 mm (6.2 in) over 16 days, compared to March's 67 mm (2.6 in) over 12 days. Humidity levels are relatively high in both months, with September at 84% and March at 80%. For more detailed information, visit Nanjin weather in March.
September and April display contrasting weather patterns. In September, temperatures range from a minimum of 17°C (63°F) to a scorching maximum of 39°C (102°F), with an average temperature of 24°C (76°F). The month is characterized by high humidity at 84% and significant rainfall, totaling 157 mm (6.2 in) over roughly 16 days. In contrast, April offers a milder climate, with temperatures varying from a minimum of 9°C (48°F) to a maximum of 36°C (96°F) and an average of 19°C (67°F). It experiences less precipitation, 121 mm (4.8 in) over about 14 days, and lower humidity at 77%. For more specific insights on April weather, you can check Nanjin weather in April.
When comparing the weather in September and May, September tends to be slightly warmer, with an average temperature of 24°C (76°F) compared to May's average of 22°C (73°F). The maximum temperatures also indicate a more intense warmth in September, reaching up to 39°C (102°F), while May peaks at 36°C (97°F). Both months experience similar levels of precipitation, with September receiving 157 mm (6.2 inches) over 16 days and May slightly less with 151 mm (6.0 inches) over the same number of days. Humidity levels are comparable as well, with September at 84% and May at 82%. For a detailed look at May's weather, you can visit Nanjin weather in May.
In comparing the weather of September and June, both months exhibit warm temperatures, with June slightly warmer on average at 25°C (77°F) compared to September's 24°C (76°F). June sees a maximum temperature of 36°C (96°F), while September's peaks can reach up to 39°C (102°F). Both months experience considerable humidity, hovering around 84% in September and 85% in June. Precipitation is also notable; September receives more rain, totaling 157 mm (6.2 in) over 16 days, in contrast to June's 134 mm (5.3 in) over the same number of days. For a closer look at the specific conditions in June, check out Nanjin weather in June.
When comparing the weather in September and July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 17°C (63°F) to a maximum of 39°C (102°F), compared to July’s higher range of 21°C (70°F) to 43°C (109°F). Additionally, September experiences a lower average temperature of 24°C (76°F) compared to July’s average of 29°C (84°F). However, September has a significant amount of rainfall at 157 mm (6.2 in) spread over 16 days, slightly less than July's 205 mm (8.1 in) over the same number of days. Both months exhibit high humidity levels, with September at 84% and July at 85%. For more detailed information, you can check Nanjin weather in July.
In comparing the weather of September to that of August, we can see some notable differences. September tends to be slightly cooler, with average temperatures around 24°C (76°F), compared to August's warmer average of 30°C (86°F). Additionally, while September's maximum temperature reaches up to 39°C (102°F), August can spike even higher, with a maximum of 41°C (107°F). Both months experience considerable precipitation, with September receiving 157 mm (6.2 in) over 16 days and August close behind at 149 mm (5.9 in) across 14 days. Humidity levels are also high, though slightly higher in August at 87%, compared to September's 84%. For more detailed information about weather trends, you can refer to Nanjin weather in August.
In September, the weather is characterized by warmer temperatures, with a minimum of 17°C (63°F) and an average of 24°C (76°F), reaching highs of up to 39°C (102°F). The month also sees significant rainfall, with 157 mm (6.2 in) over 16 days and high humidity at 84%. In contrast, October brings a noticeable drop in temperatures, with a minimum of 10°C (50°F) and an average of 18°C (65°F), peaking at 36°C (96°F). While the precipitation decreases to 108 mm (4.2 in) across the same number of rainy days, humidity also steps down slightly to 81%. For more details on October weather, check Nanjin weather in October.
In September, the weather is typically much warmer, featuring minimum temperatures of 17°C (63°F) and average highs reaching up to 39°C (102°F). This month experiences considerable precipitation, with 157 mm (6.2 in) falling over 16 days, and the humidity remains high at 84%. In contrast, November brings a notable drop in temperatures, with minimums cooling to 5°C (41°F) and average highs only reaching 25°C (77°F). Precipitation in November is significantly lower at 39 mm (1.5 in) over 9 days, and the humidity slightly increases to 86%. For more information, you can check Nanjin weather in November.
September and December present strikingly different weather conditions. In September, the temperatures range from a minimum of 17°C (63°F) to a scorching maximum of 39°C (102°F), with an average temperature of 24°C (76°F). The month experiences significant rainfall, totaling 157 mm (6.2 in) over 16 days, and humidity levels are high at 84%. In contrast, December offers a much cooler climate, with temperatures dipping as low as 1°C (35°F) and peaking at 18°C (65°F), while the average temperature settles around 9°C (49°F). Precipitation is minimal in December, at just 27 mm (1.1 in) across 7 days, accompanied by slightly lower humidity at 81%. These differences highlight the transition from the warm, wet summer to the cool, drier winter months. For more information, see Nanjin weather in December.
September in Nanjin transitions from the sweltering heat of summer to more pleasant conditions, marked by a striking blend of warmth and humidity. While temperatures can soar to a maximum of 39°C (102°F), the average drops to a more comfortable 24°C (76°F), making it a significant change from the peak summer months. The month also sees an increase in rainfall, with 16 days experiencing precipitation, contributing to the 84% humidity that can make the air feel heavy. This blend of warmth and moisture often leads to vibrant landscapes, making September a unique time to experience Nanjin's lush surroundings. For more insights on the weather patterns throughout the year, check out Nanjin Climate.